Oct. 19 will mark the 30th anniversary of Wall Street's Crash of 1987, where the Dow industrials fell some 22% in a single day -- which would be a 4,900-point drop if it happened today. In fact, stocks crashed in October 1907, 1929 and 2008 as well. Will this October be another one for the record books?

Let's review a few data points to get a feel for whether October 2017 will bring good cheer ... or rampant fear:

Stocks Are Expensive

U.S. stock valuations are currently very high by most standards.

In his most recent weekly column, John Hussman of the Hussman Funds advanced the argument that "what investors presently take as a comfortable environment of pleasant market returns and mild volatility is actually, quietly, the single most overvalued point in the history of the U.S. stock market."

In other words, the Dow and the other market indices aren't the only things at historically high levels. Stocks are historically overpriced, too.

Bonds Are Expensive, Too

Bond markets are also trading at lofty levels.

With many countries' benchmark interest rates close to zero or even negative, the Federal Reserve makes news when it talks about raising U.S. rates a lousy quarter of a percentage point.

We haven't seen the federal-funds rate above 6% since 2008, while it hasn't been at 10% since 1989. Are things really different this time, or have we reached the end of the so-called "debt supercycle"?

The stock market come November?

Lots of Red Ink

Debt is likewise at historically high levels.

Personal-, corporate- and government-debt levels are all at the breaking point, and any U.S. economic hiccup could make much of that difficult if not impossible to service. We should expect a recession to eventually hit an economy that's been expanding for eight years, but the resources that we'd need to deal with any contraction are extremely limited (if they exist at all).

Puerto Ricans are living through this right now. First they had a partial default on government obligations, and now hurricanes have devastated their island and its economy. When borrowers can't repay their debts, a new financial order must evolve.

Unfunded Pension Liability

Underfunded public and private pensions are a potential hydrogen bomb sitting at the U.S. economy's center.

It's abundantly clear that pensions are grossly underfunded, but while many people are debating ways to correct this problem, very little is actually getting done.

Unfortunately, the problem will get much worse if equity markets see a significant correction. Any loss of principal will drastically affect pension solvency, and the math will quickly become untenable.

The devastation would be immense. Personal, corporate, and governmental budgets would get busted and the whole system would need a reset.

The Markets Don't Care ... Until They Do

Of course, the North Korean crisis certainly hasn't caused markets to panic -- and if the threat of nuclear war doesn't scare investors, nothing will, right?

Perhaps, but I believe financial-market weakness will be on full display this October, which will cause uncertainty. That can lead to doubt, which could lead in turn to fear -- which sometimes results in one of the great panics that we've seen in Octobers gone by.

Consider the fact the Fitch Ratings recently downgraded the debt of Deutsche Bank DB to BBB+. This major European bank continues to struggle, but it's not the only one that's in trouble. Several Spanish and Italian banks are also barely above water. These are all cracks in a globally connected financial system.

China -- the world's No. 2 economy, is also showing signs of stress. Shadow banking accounts for 80% of the financing needed to support Beijing's GDP, but tales of fraud and abuse continue to plague Chinese investors.

Here at home, U.S. student-loan and credit-card delinquencies are on the rise. The system has absorbed the losses so far, but the future remains uncertain.

How to Play Things

The tiniest snowflake can cause an avalanche in an unstable system -- but fortunately, there's still time to prepare.

I recommend seeking out safe-haven assets like gold and silver. Resist the hype to do otherwise.

As J.P. Morgan once famously said: "Gold is money. Everything else is just credit." My advice: Hold some "real money" and watch history unfold.